1. Field of the Invention
The present invention is directed to a rotating x-ray tube having a vacuum housing with central shafts at both sides thereof, rotatably held in bearings connected to a radiator housing, and an anode rigidly connected to the vacuum housing, with a cathode arrangement mounted on a shaft attached at one side of the vacuum housing.
2. Description of the Prior Art
A rotating x-ray tube is disclosed in German OS 16 14 785 wherein the secondary coil of a filament transformer is rigidly attached to a shaft on which the cathode is mounted. The filament transformer is electrically connected to the glow (emission) helix of the cathode. The primary coil of the filament transformer concentrically surrrounds the rotating shaft, and is stationary. The shaft on which the secondary coil is mounted is rigidly joined to the rotating shaft. A disadvantage of this known structure is that the necessary connection of the glow cathode to ground must take place via a radial wiper contact, with the magnetic stray flux from this contact arrangement being extremely high.
Additionally, in this known structure it is not possible to operate two glow helices in alternation, as has now become preferable in many instances, because a separation of the magnetic circuits is extremely difficult to achieve in the known structure. Moreover, this known structure cannot be used given stationary cathodes, without inner wiper contacts being provided.